FENTANYL, 25μg/hour, transdermal patch

• In the WHO list of Essential Medicines 2025
• In the INCB List of Narcotic Drugs under International Control (Yellow list)

Strong opioid analgesic

Moderate to severe pain in patients whose pain is previously controlled with morphine or another opioid.

Prolonged opioid therapy in patients with severe renal impairment or when oral administration is not possible (dysphagia or frequent vomiting).

Fentanyl transdermal patches deliver 12 or 25 µg (mcg) of fentanyl per hour:

• a 12 µg/hour patch (2.1 mg of fentanyl) is approx. equivalent to 30-45 mg morphine over 24 hours.
• a 25 µg/hour patch (4.1-5.78 mg of fentanyl) is approx. equivalent to 60-90 mg morphine over 24 hours.

Higher-strength patches deliver 50 or 100 µg (mcg) fentanyl per hour:

• a 50 µg/hour patch (8.4.mg of fentanyl) is approx. equivalent to 120-180 mg morphine over 24 hours.
• a 100 µg/hour patch (16.8 mg of fentanyl) is approx. equivalent to 240-360 mg morphine over 24 hours.

Dosage:

• Use only in patients already receiving opioid therapy with relatively controlled pain.
• Determine the initial fentanyl dose based on the patient's 24-hour morphine equivalent.
• For paroxysmal pain attacks, administer immediate-release oral morphine (oral fentanyl is not available). Calculate the rescue dose by converting the transdermal fentanyl dose to its oral morphine equivalent, then determine the appropriate single dose.
• Monitor treatment efficacy, adverse effects, and any signs of opioid overdose.

Method of administration:

• Transdermal route
• Apply the patch to clean, dry, intact skin on a flat area of the torso or upper arms.
• Select a site where the skin is not oily and free from scars, cuts, burns, or irritations.
• If necessary, clip hair at the application site (do not shave) before the application; a non-hairy area is preferable.
• Remove the patch from the sealed pouch only immediately before use.
• Press the patch firmly with the palm of the hand for at least 30 seconds, ensuring full adhesion to the skin (especially the edges).
• Wash hands after application.
• Replace the patch every 72 hours, using a different skin site each time.

Remark:

After removal, fentanyl effects may persist for 12-18 hours; monitor the patient for signs of opioid toxicity. Systematically order naloxone (specific opioid antagonist) together with fentanyl.

Distribution to be controlled: narcotics register or supervision of amounts in and out, and storage under lock and key. (CF Introduction: Narcotic and psychotropic drugs)